Where they have been willing to protect the expectation of a particular substantive outcome, key factors that the courts appear to find influential include:
a clear and unequivocal promise, made to a single person, or a small group of people4R v North and East Devon Health Authority Ex p Coughlan [2001] QB 213. (2001).
detriment suffered by that person or group in reliance on that promise.5R (on the application of Patel) v General Medical Council [2013] EWCA Civ 327; 2013 WL 617885. (2013, March...